kernel/linux.git/drivers/usb/core/port.c, branch v6.6.150

usb: port: add delay after usb_hub_set_port_power()

2026-04-27T13:23:30+00:00

commit b84cc80610a8ce036deb987f056ce3196ead7f1e upstream. When a port is disabled, an attached device will be disconnected. This causes a port-status-change event, which will race with hub autosuspend (if the disabled port was the only connected port on its hub), causing an immediate resume and a second autosuspend. Both of these can be avoided by adding a short delay after the call to usb_hub_set_port_power(). Below log shows what is happening: $ echo 1 > usb1-port1/disable [ 37.958239] usb 1-1: USB disconnect, device number 2 [ 37.964101] usb 1-1: unregistering device [ 37.970070] hub 1-0:1.0: hub_suspend [ 37.971305] hub 1-0:1.0: state 7 ports 1 chg 0000 evt 0002 [ 37.974412] usb usb1: bus auto-suspend, wakeup 1 [ 37.988175] usb usb1: suspend raced with wakeup event <--- [ 37.993947] usb usb1: usb auto-resume [ 37.998401] hub 1-0:1.0: hub_resume [ 38.105688] usb usb1-port1: status 0000, change 0000, 12 Mb/s [ 38.112399] hub 1-0:1.0: state 7 ports 1 chg 0000 evt 0000 [ 38.118645] hub 1-0:1.0: hub_suspend [ 38.122963] usb usb1: bus auto-suspend, wakeup 1 [ 38.200368] usb usb1: usb wakeup-resume [ 38.204982] usb usb1: usb auto-resume [ 38.209376] hub 1-0:1.0: hub_resume [ 38.213676] usb usb1-port1: status 0101 change 0001 [ 38.321552] hub 1-0:1.0: state 7 ports 1 chg 0002 evt 0000 [ 38.327978] usb usb1-port1: status 0101, change 0000, 12 Mb/s [ 38.457429] usb 1-1: new high-speed USB device number 3 using ci_hdrc Then, port change bit will be fixed to the final state and usb_clear_port_feature() can correctly clear it after this period. This will also avoid usb runtime suspend routine to run because usb_autopm_put_interface() not run yet. Fixes: f061f43d7418 ("usb: hub: port: add sysfs entry to switch port power") Cc: stable@kernel.org Signed-off-by: Xu Yang Link: https://patch.msgid.link/20260316095042.1559882-1-xu.yang_2@nxp.com Signed-off-by: Greg Kroah-Hartman

USB: core: Disable LPM only for non-suspended ports

2025-01-17T12:36:22+00:00

commit 59bfeaf5454b7e764288d84802577f4a99bf0819 upstream. There's USB error when tegra board is shutting down: [ 180.919315] usb 2-3: Failed to set U1 timeout to 0x0,error code -113 [ 180.919995] usb 2-3: Failed to set U1 timeout to 0xa,error code -113 [ 180.920512] usb 2-3: Failed to set U2 timeout to 0x4,error code -113 [ 186.157172] tegra-xusb 3610000.usb: xHCI host controller not responding, assume dead [ 186.157858] tegra-xusb 3610000.usb: HC died; cleaning up [ 186.317280] tegra-xusb 3610000.usb: Timeout while waiting for evaluate context command The issue is caused by disabling LPM on already suspended ports. For USB2 LPM, the LPM is already disabled during port suspend. For USB3 LPM, port won't transit to U1/U2 when it's already suspended in U3, hence disabling LPM is only needed for ports that are not suspended. Cc: Wayne Chang Cc: stable Fixes: d920a2ed8620 ("usb: Disable USB3 LPM at shutdown") Signed-off-by: Kai-Heng Feng Acked-by: Alan Stern Tested-by: Jon Hunter Link: https://lore.kernel.org/r/20241206074817.89189-1-kaihengf@nvidia.com Signed-off-by: Greg Kroah-Hartman

USB: core: Fix access violation during port device removal

2024-05-17T10:02:28+00:00

commit a4b46d450c49f32e9d4247b421e58083fde304ce upstream. Testing with KASAN and syzkaller revealed a bug in port.c:disable_store(): usb_hub_to_struct_hub() can return NULL if the hub that the port belongs to is concurrently removed, but the function does not check for this possibility before dereferencing the returned value. It turns out that the first dereference is unnecessary, since hub->intfdev is the parent of the port device, so it can be changed easily. Adding a check for hub == NULL prevents further problems. The same bug exists in the disable_show() routine, and it can be fixed the same way. Signed-off-by: Alan Stern Reported-and-tested-by: Yue Sun Reported-by: xingwei lee Link: https://lore.kernel.org/linux-usb/CAEkJfYON+ry7xPx=AiLR9jzUNT+i_Va68ACajOC3HoacOfL1ig@mail.gmail.com/ Fixes: f061f43d7418 ("usb: hub: port: add sysfs entry to switch port power") CC: Michael Grzeschik CC: stable@vger.kernel.org Link: https://lore.kernel.org/r/393aa580-15a5-44ca-ad3b-6462461cd313@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman

usb: Disable USB3 LPM at shutdown

2024-04-27T15:11:40+00:00

commit d920a2ed8620be04a3301e1a9c2b7cc1de65f19d upstream. SanDisks USB3 storage may disapper after system reboot: usb usb2-port3: link state change xhci_hcd 0000:00:14.0: clear port3 link state change, portsc: 0x2c0 usb usb2-port3: do warm reset, port only xhci_hcd 0000:00:14.0: xhci_hub_status_data: stopping usb2 port polling xhci_hcd 0000:00:14.0: Get port status 2-3 read: 0x2b0, return 0x2b0 usb usb2-port3: not warm reset yet, waiting 50ms xhci_hcd 0000:00:14.0: Get port status 2-3 read: 0x2f0, return 0x2f0 usb usb2-port3: not warm reset yet, waiting 200ms ... xhci_hcd 0000:00:14.0: Get port status 2-3 read: 0x6802c0, return 0x7002c0 usb usb2-port3: not warm reset yet, waiting 200ms xhci_hcd 0000:00:14.0: clear port3 reset change, portsc: 0x4802c0 xhci_hcd 0000:00:14.0: clear port3 warm(BH) reset change, portsc: 0x4002c0 xhci_hcd 0000:00:14.0: clear port3 link state change, portsc: 0x2c0 xhci_hcd 0000:00:14.0: Get port status 2-3 read: 0x2c0, return 0x2c0 usb usb2-port3: not enabled, trying warm reset again... This is due to the USB device still cause port change event after xHCI is shuted down: xhci_hcd 0000:38:00.0: // Setting command ring address to 0xffffe001 xhci_hcd 0000:38:00.0: xhci_resume: starting usb3 port polling. xhci_hcd 0000:38:00.0: xhci_hub_status_data: stopping usb4 port polling xhci_hcd 0000:38:00.0: xhci_hub_status_data: stopping usb3 port polling xhci_hcd 0000:38:00.0: hcd_pci_runtime_resume: 0 xhci_hcd 0000:38:00.0: xhci_shutdown: stopping usb3 port polling. xhci_hcd 0000:38:00.0: // Halt the HC xhci_hcd 0000:38:00.0: xhci_shutdown completed - status = 1 xhci_hcd 0000:00:14.0: xhci_shutdown: stopping usb1 port polling. xhci_hcd 0000:00:14.0: // Halt the HC xhci_hcd 0000:00:14.0: xhci_shutdown completed - status = 1 xhci_hcd 0000:00:14.0: Get port status 2-3 read: 0x1203, return 0x203 xhci_hcd 0000:00:14.0: set port reset, actual port 2-3 status = 0x1311 xhci_hcd 0000:00:14.0: Get port status 2-3 read: 0x201203, return 0x100203 xhci_hcd 0000:00:14.0: clear port3 reset change, portsc: 0x1203 xhci_hcd 0000:00:14.0: clear port3 warm(BH) reset change, portsc: 0x1203 xhci_hcd 0000:00:14.0: clear port3 link state change, portsc: 0x1203 xhci_hcd 0000:00:14.0: clear port3 connect change, portsc: 0x1203 xhci_hcd 0000:00:14.0: Get port status 2-3 read: 0x1203, return 0x203 usb 2-3: device not accepting address 2, error -108 xhci_hcd 0000:00:14.0: xHCI dying or halted, can't queue_command xhci_hcd 0000:00:14.0: Set port 2-3 link state, portsc: 0x1203, write 0x11261 xhci_hcd 0000:00:14.0: Get port status 2-3 read: 0x1263, return 0x263 xhci_hcd 0000:00:14.0: set port reset, actual port 2-3 status = 0x1271 xhci_hcd 0000:00:14.0: Get port status 2-3 read: 0x12b1, return 0x2b1 usb usb2-port3: not reset yet, waiting 60ms ACPI: PM: Preparing to enter system sleep state S5 xhci_hcd 0000:00:14.0: Get port status 2-3 read: 0x12f1, return 0x2f1 usb usb2-port3: not reset yet, waiting 200ms reboot: Restarting system The port change event is caused by LPM transition, so disabling LPM at shutdown to make sure the device is in U0 for warmboot. Signed-off-by: Kai-Heng Feng Cc: stable Link: https://lore.kernel.org/r/20240305065140.66801-1-kai.heng.feng@canonical.com Signed-off-by: Greg Kroah-Hartman

USB: core: Fix deadlock in port "disable" sysfs attribute

2024-04-03T13:29:00+00:00

commit f4d1960764d8a70318b02f15203a1be2b2554ca1 upstream. The show and store callback routines for the "disable" sysfs attribute file in port.c acquire the device lock for the port's parent hub device. This can cause problems if another process has locked the hub to remove it or change its configuration: Removing the hub or changing its configuration requires the hub interface to be removed, which requires the port device to be removed, and device_del() waits until all outstanding sysfs attribute callbacks for the ports have returned. The lock can't be released until then. But the disable_show() or disable_store() routine can't return until after it has acquired the lock. The resulting deadlock can be avoided by calling sysfs_break_active_protection(). This will cause the sysfs core not to wait for the attribute's callback routine to return, allowing the removal to proceed. The disadvantage is that after making this call, there is no guarantee that the hub structure won't be deallocated at any moment. To prevent this, we have to acquire a reference to it first by calling hub_get(). Signed-off-by: Alan Stern Cc: stable Link: https://lore.kernel.org/r/f7a8c135-a495-4ce6-bd49-405a45e7ea9a@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman

usb: port: Don't try to peer unused USB ports based on location

2024-04-03T13:28:42+00:00

commit 69c63350e573367f9c8594162288cffa8a26d0d1 upstream. Unused USB ports may have bogus location data in ACPI PLD tables. This causes port peering failures as these unused USB2 and USB3 ports location may match. Due to these failures the driver prints a "usb: port power management may be unreliable" warning, and unnecessarily blocks port power off during runtime suspend. This was debugged on a couple DELL systems where the unused ports all returned zeroes in their location data. Similar bugreports exist for other systems. Don't try to peer or match ports that have connect type set to USB_PORT_NOT_USED. Fixes: 3bfd659baec8 ("usb: find internal hub tier mismatch via acpi") Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218465 Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218486 Tested-by: Paul Menzel Link: https://lore.kernel.org/linux-usb/5406d361-f5b7-4309-b0e6-8c94408f7d75@molgen.mpg.de Cc: stable@vger.kernel.org # v3.16+ Signed-off-by: Mathias Nyman Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218490 Link: https://lore.kernel.org/r/20240222233343.71856-1-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman

usb: core: add sysfs entry for usb device state

2023-06-13T09:58:26+00:00

Expose usb device state to userland as the information is useful in detecting non-compliant setups and diagnosing enumeration failures. For example: - End-to-end signal integrity issues: the device would fail port reset repeatedly and thus be stuck in POWERED state. - Charge-only cables (missing D+/D- lines): the device would never enter POWERED state as the HC would not see any pullup. What's the status quo? We do have error logs such as "Cannot enable. Maybe the USB cable is bad?" to flag potential setup issues, but there's no good way to expose them to userspace. Why add a sysfs entry in struct usb_port instead of struct usb_device? The struct usb_device is not device_add() to the system until it's in ADDRESS state hence we would miss the first two states. The struct usb_port is a better place to keep the information because its life cycle is longer than the struct usb_device that is attached to the port. Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-lkp/202306042228.e532af6e-oliver.sang@intel.com Reviewed-by: Alan Stern Signed-off-by: Roy Luo Message-ID: <20230608015913.1679984-1-royluo@google.com> Signed-off-by: Greg Kroah-Hartman

usb: core: stop USB enumeration if too many retries

2022-11-08T15:50:21+00:00

When a broken USB accessory connects to a USB host, usbcore might keep doing enumeration retries. If the host has a watchdog mechanism, the kernel panic will happen on the host. This patch provides an attribute early_stop to limit the numbers of retries for each port of a hub. If a port was marked with early_stop attribute, unsuccessful connection attempts will fail quickly. In addition, if an early_stop port has failed to initialize, it will ignore all future connection events until early_stop attribute is clear. Signed-off-by: Ray Chi Reviewed-by: Alan Stern Link: https://lore.kernel.org/r/20221107072754.3336357-1-raychi@google.com Signed-off-by: Greg Kroah-Hartman

usb: core: Use kstrtobool() instead of strtobool()

2022-11-03T14:46:01+00:00

strtobool() is the same as kstrtobool(). However, the latter is more used within the kernel. In order to remove strtobool() and slightly simplify kstrtox.h, switch to the other function name. While at it, include the corresponding header file () Signed-off-by: Christophe JAILLET Link: https://lore.kernel.org/r/f01ef2ddaf12a6412127611617786adc1234e0b4.1667336095.git.christophe.jaillet@wanadoo.fr Signed-off-by: Greg Kroah-Hartman

usb: hub: port: add sysfs entry to switch port power

2022-06-12T04:49:46+00:00

In some cases the port of an hub needs to be disabled or switched off and on again. E.g. when the connected device needs to be re-enumerated. Or it needs to be explicitly disabled while the rest of the usb tree stays working. For this purpose this patch adds an sysfs switch to enable/disable the port on any hub. In the case the hub is supporting power switching, the power line will be disabled to the connected device. When the port gets disabled, the associated device gets disconnected and removed from the logical usb tree. No further device will be enumerated on that port until the port gets enabled again. Reviewed-by: Alan Stern Signed-off-by: Michael Grzeschik Link: https://lore.kernel.org/r/20220607114522.3359148-1-m.grzeschik@pengutronix.de Signed-off-by: Greg Kroah-Hartman